Solution of cellulose esters



Patented Oct. 4, 1927.

UNI-TED STATES PATENT OFFICE.

JOSEPH G. DAVIDSON, OF YONKEBS, NEW YORK, ASSIGNOR T CARBIDE AND CARBON CHEMICALS CORPORATION, A CORPORATION OF NEW YORK.

SOLUTION OF CELLULOSE ESTERS.

No Drawing.

- The invention relates to solutions of cellulose esters such as are employed, for example, as lacquers, lacquer enamels, and dopes for airplane fabrics; and its ob]ect 6 is to provide improved compositions of this.

' class.

Many solvents for cellulose esters, such as the nitrate and acetate esters, are known. Butyl and amyl acetates are often used;

, l0 and acetylene tetrachlorid, ethylene chlorhydrin, .and diacetone alcohol,

CI-I COCH COH CH where R stands for an alkyl or aryl group,

or a hydrogen atom, and R stands for an alkylor aryl group. The di-ethers are distinguished from the acetals of the same empirical formula by having the ether linkages on different carbon atoms. The structural formulas are not certainly known, but it is believed that the mono-ethers are chiefly or solely of the type (m-on tam-on.

Examples of the ethers of pro lene lycol 60 are the monomethyl ether. C, ,OH. CH (b. p. 122.8 (3.), the 'monoethyl ether C H QHDC H (b. p. 133.0 0.), the mono isopro yl ether, (b. p. 141.5 (1.), the mono .norma propyl ether (b. p. 150.0 (1;, the 5 mono isobutyl ether (b. p. 161.3 C. the mono normal butyl ether.(b. p. 170.6 (1), the mono isoamyl ether (b. p. 183.3 C.), the dimethyl ether (3 H (OCH,) and the diethyl ether. The above boiling W at 736 mm. pressure. The aryl et are, e. g. the monophenyl ether'('J,.H.,OH.OC..H, .and the mono enzyl ether C,H..OH.OGH,C,H,, are also good solvents for cellulose esters.

When used for dissolving cellulose esters,

oints are- Application mm. 20, 1925. Serial No. 44,928.

the ethers-of propylene glycol have the advantage of hi h solvent ower; freedom from disagreeafile odors suc as characterize butyl and amyl acetates; ability to form free-flowing solutions; and miscibility with most of the common and chea They contain no acid radiclean therefore do not hydrol ze. The mono-others surpass the di-ethers 1n solventpower. 7

The propylene glycol ethers may be used in conjunction with a. wide variety'of other solvents or diluents in the pro aration of lacquers and the like. Because 0 their high solvent power a .large proportion of cheap diluent, such as gasoline or benzene, may often be used. A high-boiling solvent, such as is commonly used in small'proportion in conjunction with known solvents for cellulose esters, may also be used in conjunction with the propylene glycol ethers, and other expedients employed in the lacquer industry are likewise applicable in glycol ethers are employe Instead of a pure or nearly pure propylene glycol ether I may use a mixture, such as a mixture of monoand di-ethers with solvents.

(general where the L the same or diflerent ether groups. Mixtures containing the others of propylene glycol together with one or more ethers of another glycol or glycols, e. g. the ethylene and butylene lycols, are also valuable sol- Vents for cellu ose esters. Such mixtures can be prepared working up a raw material b which is itself a mixture. For example, a mixture of olefin oxide can be prepared by appropriate steps from a mixture of olefin's and the olefine oxides can be used for.

makin ethers by causing them to react with alcoho s in the manner more fully described in my' application Serial No. 44,929.

I e um: I 1. A composition of matter comprising a solution of cellulose ester containing a substantial proportion of an ether of propylene glycol.

- 2.-A composition of matter comprising a solution of cellulose ester containing a sub-'.

stantial proportion of an alkyl ether of propylene glycol.

3. A composition of matter comprising a '4. A composition of matter comprising a i solution of cellulose ester containing a substantial pro ortion of a. monoalkyl ether of propylene g ycol.

5. A composition of matter comprising a solutionof cellulose ester containing a sub-- stantial quantity of a propylene glycol ether represented by the forum a where is a methyl or ethyl group.

6. A composition of matter comprising a solution of cellulose ester containing a substantial proportion of a monoethyl ether of a propylene glycol.

In testimony whereof, I aifix my signature.

JOSEPH GFDAVIDSON. 

